diff options
| author | Maxim Kiselev <bigunclemax@gmail.com> | 2021-02-17 14:10:00 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-03-04 12:15:37 +0100 |
| commit | b81946ec1157346545f682e3c742d47d2d554333 (patch) | |
| tree | e2f14d0b29df062151de730222f5e982025e09a1 | |
| parent | 155796e9519cdcd0afb0ce758a26e714a13628e0 (diff) | |
gpio: pcf857x: Fix missing first interrupt
commit a8002a35935aaefcd6a42ad3289f62bab947f2ca upstream.
If no n_latch value will be provided at driver probe then all pins will
be used as an input:
gpio->out = ~n_latch;
In that case initial state for all pins is "one":
gpio->status = gpio->out;
So if pcf857x IRQ happens with change pin value from "zero" to "one"
then we miss it, because of "one" from IRQ and "one" from initial state
leaves corresponding pin unchanged:
change = (gpio->status ^ status) & gpio->irq_enabled;
The right solution will be to read actual state at driver probe.
Cc: stable@vger.kernel.org
Fixes: 6e20a0a429bd ("gpio: pcf857x: enable gpio_to_irq() support")
Signed-off-by: Maxim Kiselev <bigunclemax@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/gpio/gpio-pcf857x.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c index a2a8d155c75e..b7568ee33696 100644 --- a/drivers/gpio/gpio-pcf857x.c +++ b/drivers/gpio/gpio-pcf857x.c @@ -332,7 +332,7 @@ static int pcf857x_probe(struct i2c_client *client, * reset state. Otherwise it flags pins to be driven low. */ gpio->out = ~n_latch; - gpio->status = gpio->out; + gpio->status = gpio->read(gpio->client); /* Enable irqchip if we have an interrupt */ if (client->irq) { |